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Displaying 21601 - 21625 of 73830

Demonstration of Achromatic Cold-Neutron Microscope Utilizing Axisymmetric Focusing Mirrors.

April 21, 2013
Author(s)
Daniel S. Hussey, D. Liu, M. V. Gubarev, D Ramsey, David L. Jacobson, Muhammad D. Arif, D. E. Moncton, B. Khaykovich
An achromatic cold-neutron microscope with magnification 4 is demonstrated. The image-forming optics is made of nested coaxial mirrors of full figures of revolution, so-called Wolter optics. The spatial resolution, field of view, and depth of focus are

The SIM time scale

April 20, 2013
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero, Nelida Diaz-Munoz, E. de Carlos-Lopez
Time measurement is of great importance for science, technology and commerce. Among the seven base units of the International System (SI), the second can be realized with the smallest uncertainty, currently reaching parts in 10 16. Keeping track of the

Universal Proteolysis and MSn for N- and O- Glycan Branching Analysis

April 20, 2013
Author(s)
John E. Schiel, Karen W. Phinney, Nicholas J. Smith
The continually growing list of critical glycosylation-related processes has made analytical methodology for detailed glycan characterization an area of increasing interest. Glycosylation is a post translational modification of unsurpassed complexity due

Effect of Surface Chemistry on Stem Cell Response in 2-D vs. 3-D Cell Culture Niches

April 19, 2013
Author(s)
Sumona Sarkar, Carl G. Simon Jr., Roberta I. Lock, Joy P. Dunkers
To develop tissue engineered devices for regenerative medicine strategies, key scaffold properties for directing stem cell response must be identified. As focus shifts from 2-D to 3-D culture systems in an attempt to better recapitulate the natural

Sustainability through Lifecycle Synthesis of Material Information

April 19, 2013
Author(s)
Paul W. Witherell, Katherine C. Morris, Anantha Narayanan Narayanan, Jae H. Lee, Sudarsan Rachuri
The synthesis of material information across lifecycle stages will lay the foundation for a material information model to support sustainable decision making. This paper explores how material information is represented in select standards that address

A Sensor Ontology Literature Review

April 18, 2013
Author(s)
Roger D. Eastman, Craig I. Schlenoff, Stephen B. Balakirsky, Tsai H. Hong
The purpose of this paper is to review existing sensor and sensor network ontologies to understand whether they can be reused as a basis for a manufacturing sensor ontology, or if the existing ontologies hold lessons for the development of a new ontology

Assessing Ranging Errors as a Function of Azimuth in Laser Trackers and Tracers

April 18, 2013
Author(s)
Balasubramanian Muralikrishnan, Vincent D. Lee, Christopher J. Blackburn, Daniel S. Sawyer, Steven D. Phillips, Wei Ren, Ben Hughes
Tilt and radial error motion of a laser tracker head as it spins about the two axes results in small but measurable ranging and angle errors. The laser tracer, on the other hand, measures range with respect to the center of a high quality stationary sphere

Determining Mechanical Reliability of Brittle Materials

April 18, 2013
Author(s)
Stephen W. Freiman, Jeffrey Fong
The widespread existence of slow crack growth in most glasses and ceramics due to a stress-enhanced reaction between an external environment and strained bonds at a crack tip greatly complicates the challenge of assuring the reliability of components which

Fast, Optically Controlled Kerr Phase Shifter for Digital Signal Processing

April 18, 2013
Author(s)
Runbing Li, Lu Deng, Edward W. Hagley, Joshua Bienfang, Zachary H. Levine, Marvin G. Payne
We demonstrate an optically controlled Kerr phase shifter using a room-temperature Rb85 vapor operating in a Raman gain scheme. Phase shifts from zero to 𝜋 relative to an unshifted reference wave are observed, and gated operations are demonstrated. We

Guidelines for Evaluating Fire Blocking Barrier Fabrics

April 18, 2013
Author(s)
Shonali Nazare, William M. Pitts, Shaun M. Flynn, Rick D. Davis, John R. Shields
This document provides guidelines to quantify fire performance properties of fire blocking barrier materials used in soft furnishings. In an attempt to enable a priori selection of fire barrier materials such that the final upholstered product complies

Micro/nano-wear studies on epoxy/silica nanocomposites

April 18, 2013
Author(s)
Zhengzhi Wang, Ping Gu, Xiao-ping Wu, Zhong Zhang, Martin Chiang, Hui Zhang
We proposed a new method for quantifying the micro/nano-scale wear volume (i.e., volume of wear loss) in a test to characterize the wear-resistance of nanocomposites. Effects of wear load and pass (a pattern of scan cycles), and nanoparticle content on the

Tungsten L Transition Line Shapes and Energy Shifts Resulting from Ionization in Warm Dense Matter

April 18, 2013
Author(s)
Lawrence T. Hudson, John F. Seely, Bruce V. Weber, D. G. Phipps, Nino R. Pereira, D Mosher, K. Slabkowska, M. Polasik, J Rzadkiewicz, S Hansen, Uri Feldman, Joseph W. Schumer
High resolution spectra of the W L transitions in the energy range 8 keV to 12 keV from warm dense plasmas generated by the Naval Research Laboratory’s Gamble III pulsed power machine were recorded by a transmission-crystal x-ray spectrometer with ± 2 eV

Performance of Steel Shear Tab Connections at Elevated Temperatures

April 16, 2013
Author(s)
Mina S. Seif, Joseph Main, Therese P. McAllister
At the present time, there is a lack of understanding of the performance of structures as complete systems under extreme loading conditions such as realistic, uncontrolled fires. Current specifications for the design of steel structures in the U.S. do not

EFFECT OF HIGH LUMINANCE SOURCES TO PERIPHERAL ADAPTATION STATE IN MESOPIC RANGE

April 15, 2013
Author(s)
Tatsukiyo (. Uchida, Yoshihiro Ohno
CIE 191:2010 recommends a mesopic photometry system that defines the spectral luminous efficiency function for peripheral visual tasks. For implementation of the system, the visual adaptation field, which takes into account the surrounding luminance effect

Microfabricated Atomic Magnetometers

April 15, 2013
Author(s)
Svenja A. Knappe, John E. Kitching
In this chapter, we discuss miniaturized atomic magnetometers, and the technology and applications relevant to this somewhat unusual direction in magnetometer research and development. By “miniaturized”, we mean, in addition to their size, magnetometers

Nuclear magnetic resonance gyroscopes

April 15, 2013
Author(s)
Elizabeth A. Donley, John E. Kitching
This review begins with an introduction to NMR gyroscopes (NMRGs), followed by a discussion of the frequency shifts and relaxation mechanisms that determine and their performance. Specific NMRG implementations are then reviewed, including dual NMR species

SEISMIC FRAGILITY AND COST ANALYSES OF ACTIVELY CONTROLLED STRUCTURES

April 15, 2013
Author(s)
Kevin K. Wong, John L. Harris
Seismic fragility represents the probability that the structural response exceeds a given performance limit state due to a specified intensity of ground motion, and it has a direct relationship with the cost of rehabilitating the structural system. In this
Displaying 21601 - 21625 of 73830
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